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CZ-Synthetic


#1
   Um....actually, CZ is a synthetic, not a simulant. 

I was under the impression that to be a synthetic, the man made
stone is made of the same properties as a natural occurring stone or
mineral with the same exact properties. What natural stone possess
the same chemical properties and RI, Specific gravity and MOH
hardness of CZ??? Or have I missed a natural CZ somewhere? Oh wait I
forgot “diamondeque or is that diamondyuck”! Respectfully Kenneth
Ferrell


#2
  Um....actually, CZ is a synthetic, not a simulant. 

No, it’s a simulant, not a synthetic! Synthetics are chemically the
same as the real thing, only they’re man-made. Simulants pretend to
be the real thing but are chemically different. CZs are not composed
of carbon, yet they like to masquerade as diamonds; that makes them
simulants.

Beth


#3

Kenneth, You are correct of course that to be a synthetic a material
must have a natural; counterpart. CZ’s natural counterpart is
baddeleyite, a stable monoclinic form of zirconium oxide.

Jerry in Kodiak


#4
              Um....actually, CZ is a synthetic, not a simulant.
No, it's a simulant, not a synthetic!  Synthetics are chemically
the same as the real thing, only they're man-made.  Simulants
pretend to be the real thing but are chemically different.  CZs are
not composed of carbon, yet they like to masquerade as diamonds;
that makes them simulants. 

Well, Actually, it’s both. CZ is a simulated diamond, not a synthetic
diamond. But the C.Z. we use is correctly called synthetic cubic
zirconia, since it’s a chemically (or closely enough to it) identical
lab made version of natural cubic zirconia.

In all likelyhood, you’ve not heard of natural cubic zirconia. It’s
not commonly found as anything larger than microscopic grains, or as
a trace mineral. I seem to recall reading somewhere that the best
crystal specimins found (about small sand grain size if I remember it
right) were in meteorites. Terrestrial sources include trace amounts
found as a byproduct of the breakdown of metaminct zircon. Usually,
however, zirconium oxide is found in the tetragonal crystal system,
not the cubic one. Still, since it HAS been found, even if only
once, the synthetic stuff we know and love (or loathe) can still be
properly called synthetic cubic zirconia rather than just a diamond
simulant.

Peter Rowe


#5

Hello All: Synthetic cubic zirconia is a man-made material. Natural
cubic zirconia has only been found as inclusions in zircon. Although
it is used as a simulant for diamond it is synthetic.
Michael R. Mathews Sr. Victoria,Texas USA


#6

CZ is a funny one. When CZs were invented, they were indeed a
diamond simulant. However, after the invention, someone mined
natural CZ. So now the cheap stuff we buy is synthetic CZ.
That’s what they teach at GIA.

Elaine Luther
Chicago area, Illinois, USA
Metalsmith, Certified PMC Instructor
Studio 925; established 1992
@E_Luther


#7

Seems to me CZ’s are both. A man-made (synthetic) stone, intended
to be a diamond look-alike. Therefore, a synthetic diamond simulant.
Or, a synthetic diamond imitation, or…


#8

The point that a number of people have tried to point out is that a
synthetic is not only manmade, but has a natural counterpart. The
simulant not only simulates the natural stone, but is chemically and
crystalographically identical. I don’t think that anyone around here
is familiar with a natural form of cubic zirconia. Are you?

Bruce D. Holmgrain
JA Certified Master Bench Jeweler
http://www.goldwerx.com


#9

I always understood that the distinction in the gem world went like
this: A synthetic is a lab grown (ie, man made) copy of the genuine
article. Identical to the natural in crystallography and chemistry,
just grown under lab conditions instead of the ground. A simulant is
still man made, usually, but only looks like the natural stone it is
intended to simulate. There is not necessarily even any remote
similarity in crystal structure or chemistry. It is merely appearance.


#10
    I was under the impression that to be a synthetic, the man
made stone is made of the same properties as a natural occurring
stone or mineral with the same exact properties. What natural stone
possess the same chemical properties and RI, Specific gravity and
MOH hardness of CZ??? Or have I missed a natural CZ somewhere? Oh
wait I forgot "diamondeque or is that diamondyuck"! Respectfully
Kenneth Ferrell 

Yes, Kenneth. Man-made CZ has the same chemical, optical and
physical properties as the natural mineral. I’m afraid that,
according to what I was taught at GIA, you did indeed miss a natural
CZ somewhere. Respectfully, James Duncan.


#11
    No, it's a simulant, not a synthetic!  Synthetics are
chemically the same as the real thing, only they're man-made. 
Simulants pretend to be the real thing but are chemically
different.  CZs are not composed of carbon, yet they like to
masquerade as diamonds; that makes them simulants. 

Yes, Beth. I admitted I was wrong in saying that it isn’t a
simulant. It most certainly is! However, it does have a very rare
natural counterpart, therefore it is also a synthetic.

James Duncan.


#12

According to Kurt Nassau naturally occurring CZ has been found in
minute quantities within natural zircon crystals. The presence of the
natural cubic form of zirconium oxide (CZ) was identified via x-ray
diffraction techniques in 1937 by Stackelberg and Chudoba.

Since most CZ is synthesized in laboratories or factories by man I
would think that it falls under the “synthetic” heading. It also
falls under the “simulant” heading when used to simulate diamond
which is a completely different mineral with similar optical
properties to CZ. What makes CZ such a good diamond simulant ARE its
similar optical properties.

In light of the above, the cubic form of zirconium oxide (CZ or
Cubic Zirconia) does occur naturally, is mostly manmade and thus a
synthetic, and often is used to simulate diamonds.

Steve Green / Rough and Ready Gems www.briolettes.com Your source
for fine colored gemstone briolettes and precision ultrasonic
drilling.


#13

Quotes from a couple of others here…

The simulant not only simulates the natural stone, but is
chemically and crystalographically identical."  and "A simulant is
still man made..." 

Not so, for example natural white sapphire was often used to
simulate diamond.

Simulation is about the purpose the material is put to.

Synthesis refers to the process that makes it.

Now, where can I get hold of, say, 50 carats of these new synthetic
diamonds…anyone?

Tony Konrath
Key West Florida 33040


#14

Hi Tony,

Now, where can I get hold of, say, 50 carats of these new synthetic
diamonds....anyone? 

If you’re looking for yellow diamonds, try Gemisis. Don’t have their
address, but they’re located in Florida.

Dave


#15

Fellow Orchidinites,

Maybe I don’t know the definition of a synthetic gem, so I ask; Where
is it written that a synthetic gem has to have a natural
counterpart?

In my way of thinking “synthetic” comes from the word synthesis
which means - the act of putting together… in this case by man.

Currently I would call any synthesized gem whether it has a natural
counterpart or not a synthetic gem.

I’ll bet that anything Man can synthesize exists in Nature anyway
whether we have found it or not. Man uses and obeys the laws of
Nature for everything he does. High tech or not everything we do is
done within this framework.

Maybe I am overlooking something here and this is not the case. If
so please explain it to me.

Steve Green - Rough and Ready Gems www.briolettes.com I have a few
synthetic CZ & citrine briolettes, but everything else is “natural”.


#16

Steve,

Most, if not all, of the gemological textbooks do define a synthetic
gem as something exactly duplicating its natural counterpart.
Simulants are defined as something that is made to be similar in look
to something natural, but not made of the same material.
Unfortunately it doesn’t really matter how you personally define
synthesis–from the gemological standpoint it is quite clearly
defined–and thank goodness it is because if we all decided to ignore
scientific definitions no one would know what anyone else was talking
about.

Daniel R. Spirer, GG
Spirer Somes Jewelers
1794 Massachusetts Ave
Cambridge, MA 02140
617-491-6000
@spirersomes
www.spirersomes.com


#17

Hello Steve and All:

The following is a quote from lesson 4 of my colored stones course
from GIA.

"First -as always -we need to be clear about our product. A
synthetic gem has two basic qualities:

  1. It is an artificial (manmade) material.

  2. It has essentially the same chemical composition and structure as
    some natural gem.

The similar compositions and structures produce similar physical,
optical, and chemical characteristics. Thus, a synthetic ruby weighs
the same as a natural ruby the same size. It affects light in
basically the same way. And it reacts to chemicals and heat the same
way. However, slight differences in characteristics let gemologists
separate synthetics from their natural couterparts.

This one-to-one correspondence of man- made and natural makes a true
synthetic. Using a material merely to imitate a natural gem does not
make it a synthetic, just an imitation.

Some manmade materials have no natural couterparts. They do not
duplicate the composition and structure of any known natural gem.
Technically, although man-made, they are not synthetics."


#18
    Maybe I don't know the definition of a synthetic gem, so I
ask; Where is it written that a synthetic gem has to have a natural
counterpart? 

Hi Steve. It is written in Richard T. Liddicoat, Jr.'s handbook of
Gem Identification, p. 85: "A synthetic gem material has the same
chemical composition, crystal structure, and consequently, the same
physical and optical properties of the natural gem it represents."
Another similar quote can be found in GIA’s Diamonds and Diamond
Grading course, Lesson 18, p. 2, which would be redundant to quote
here.

    In my way of thinking "synthetic" comes from the word
synthesis which means - the act of putting together... in this case
by man. 

Your way of thinking differs somewhat from Merriam- Webster’s
Dictionary. Their definition as applies to this discussion is as
follows:

of, relating to, or produced by chemical or biochemical syntheses:
especially : produced artificially (2) : of or relating to a synfuel b : devised, arranged, or
fabricated for special situations to imitate or replace usual
realities c : FACTITIOUS, BOGUS

   Currently I would call any synthesized gem whether it has a
natural counterpart or not a synthetic gem. 

Both Liddicoat’s and M-W’s definitions insist that a synthetic has a
natural counterpart. You can’t argue with the actual definition.

    I'll bet that anything Man can synthesize exists in Nature
anyway whether we have found it or not. Man uses and obeys the laws
of Nature for everything he does. High tech or not everything we do
is done within this framework. 

With the size of the universe being what it is, there’s no telling
how many things are out there, so this statement is probably quite
correct.

    Maybe I am overlooking something here and this is not the
case. If so please explain it to me. 

I don’t know you, Steve, so I’m not certain of any gemological
training you may have had, but I sure do enjoy your posts here! The
problem with synthetics and simulants is that most are (at least
initially) designed to fool the public into thinking that they are
natural It was a recent experience of mine that an
acquaintance brought to me a faceted stone that simply swept her off
her feet. It was a lovely green rectangle-cut stone, labeled:
Tsavorite-Colored, Lab-Created Obsidian. She almost fell out of her
chair when I had to tell her that it was a very beautiful piece of
faceted glass. Of course, everybody knows that “lab-created” means
basically the same as “synthesized”, so she thought she was getting
something that was created by some arcane laboratory process. Sure,
it was synthesized, or “put together…in this case by man”, but
obsidian is, in fact, a natural form of glass. “Lab-created
obsidian” would be, by definition, glass. The only thing that you
have overlooked may be that, if a scientist develops a substance
that has all the same properties of a natural one, it was
synthesized. If that same scientist develops a substance that has no
parallel in nature, it’s called an invention.

Respectfully, James Duncan


#19

Steve, In answer to your question “Where is it written that a
synthetic gem must have a natural counterpart?” , the fifth edition
of Webster’s “Gems, their sources, descriptions and identification”,
fifth edition p. 389 states “as a natural counterpart must exist, a
synthetic stone will have the same chemical and physical
properties”…etc.Further Liddicoat’s “Handbook of
Gem Identification” 12th edition, p. 7 states"“By definition, both
the chemical composition and crystal structure of a synthetic are
identical to those of the natural stone it represents.” My question
would be, “Where is it written to the contrary?”

Jerry in Kodiak
Steve Green wrote:


#20

Hello Daniel,

Most, if not all, of the gemological textbooks do define a 	
synthetic gem as something exactly duplicating its natural 	
counterpart. 

Richard Liddicoat et al do indeed describe a synthetic stone as
duplicating or reproducing a gem however Peter G Read more correctly
uses the term synthetically-produced stone, synthetically-grown and
synthetically-created are also correct. When describing a boule or a
grown crystal you may correctly refer to synthetic ruby, C.Z. or
whatever but once it is cut into a stone or gem the English is
wrong.

The most correct term is man made which covers all cut or uncut
synthetics, most simulants and the lab uniques such as strontium
titanate, lithium niobate and the lovely garnet twins, yttrium
aluminium garnet and gadolinium gallium garnet.

Tony.
In dry dry B.C. where our forest is still burning.